Guard-hood for parallelly spaced apart dental teeth grinding discs



- y 8, 1956 s. BIRNBAUM 2,744,327

GUARDHOOD FOR PARALLELLY SPACED APART DENTAL TEETH GRINDING DISCS Filed Dec. 9, 1954 I N V EN TOR. 5444051. 3/8/08 4! irra/ave/a United GUARD-HOOD FOR PARALLELLY SPACED APART DENTAL TEETH GRINDING DISCS This invention relates to an improved guard-hood for rotary drill cutting means such as used to obtain parallelism of abutment surfaces between natural teeth and bridgework in an occ'luso-gingival direction, and more particularly to such improved guard-hood for spaced apart parallelly aligned grinding discs mounted for rotation in unison on a driven mandrel attached for operation to a leading end of a conventional manually directed engine drill head of any well understood construction.

Among the objects of the invention is to generally improve guard-hoods of the character described which shall comprise few and simpleparts, which shall be readily assembled and easily adjusted to engine drill heads for safeguarding and shielding the tongue, gums and other mouth portions adjacent natural teeth being ground to obtain parallelism of the abutment surfaces between said natural teeth and bridgework in an occluso-gingival direction, and which shallbe practical and eflicient to a high degree 1n use.

Other objects of the invention will in and in part hereinafter pointed out.

The invention accordingly consists of features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter disclosed, the scope of the application of which will be indicated in the claims following.

This invention is a continuation in part of applicants invention SerialNo. 372,949, filed August 7, 1953, for Cutting Means and Method for Preparing Natural Teeth for Bridgework. i

In the accompanying drawing in which an embodiment of the invention is shown:

Figs. 1, 2, 3 and 4 are side elevational, front end, rear end and top plan views, respectively, of a guard-hood constructed to embody the inventionremoved from a dental engine drill head provided with spaced apart parallelly aligned grinding discs mounted for rotation in unison, as is clear from Fig. 6 and the disclosure set forth in said application Serial No. 372,949.

Fig. 5 is an enlarged perspective view of the improved guard-hood construction shown in detailed assembly.

part be obvious Fig. 6 is a side elevational view of a fragmentary por:

tion of a conventional manually operated power driven drill head showing the assembly mounting of adjustably spaced apart parallelly aligned grinding discs on an arbor or mandrel as positioned during the preparation for fitting bridgework insimultaneously cutting parallel slices in an accluso-gingival direction on the natural teeth bridge abutment sides, onlya fragmentary portion of the jaw and teeth being shown, said assembly being fitted with the improved guard-hood embodying the invention in an effective position for protecting the tongue, gums and mouth portions adjacent said natural teeth against injury, and

Fig. 7. is an enlarged cross-sectional view of the drill head andirnproved guard-hood taken on line 7--7 in Fig. 6.

Referring in detail to the drawing, 10 denotes a rotary drill cutting means having parallelly spaced apart dental grinding discs 10a and 10b equipped with an improved guard-hoodll constructed to embody the invention. As is clear from Fig. 5, said rotary drill cutting means 10 is attached for operation to a leading end of a conventional manuallydirected dental power engine drill head H in any well understood manner.

rates Patent 2,744,327 la e y 8, 1956 Said cutting means 10 is seen to include an elongated into and to. be detachably secured to turn with a chuck portion of the drill head H on supplying motor power in the well understood manner. Said spindle shaft may be provided with suitable means for replaceably mounting and adjusting in desired spaced apart parallelly aligned relation thereon said pair of grinding discs 10a and 10b. As here shown, spindle shaft 100 which extends beyond drill head H may be formed with a threaded end portion ltlj of reduced diameter extending beyond an abutment shoulder 10h to form said grinding discs mounting means When provided with backing clamping nuts 10a and 10f and an end nut 10g, as shown in Fig. 6.

Back clamping nuts 10c and 10 may each have radially extending flanges for bracing the rear or smooth sides of 'discs 10a and 10b, respectively, opposite grinding or abrasive surfaces 10k and 10m, respectively.

Mandrel 10d when provided with threaded end portion 10 as above described, with nuts 10e, 10f and 10g can be adjustably assembled to rigidly support grinding discs 10a and 10b in parallelly aligned planes for rotation with the chuck portion of drill head H and have disc abrasive surfaces 10k and 10m positioned a desired spaced apart distance as required for simultaneously cutting parallel slices in an occluso-gingival direction on sides A and B of surface abutments of natural teeth T between and against which permanent bridgework W (indicated in dot and quired anchoring grooves and pits (not shown) provided in the natural teeth T in the well understood manner.

Guard-hood 11, as is clear from Figs. 1 to 7, may comprisea base element 11a which has a suitable tubular anchoring member 11b, here shown as having an end sleeve 11c frictionally mounted on drill head H and extending to allow free rotation of mandrel 10d extending axially therethrough.

Rim edge 11d of sleeve 11c may be notched, that is, cut back to engage about screw head He projecting up from drill head H to more positively prevent accidental rotary movement of end sleeve 110 from its frictional mounting thereon. A sleeve end of said anchoring member 11b opposite said end sleeve 11c may be extended about spindle shaft 100 and terminate in a support rest 11g of enlarged diameter and arcuate cross-sectional shape, a peripherally extending out-turned flange 11h being provided to extend beyond surface 11 thereof extending transverse with respect to axis X--X of rotation of mandrel 10d and in a radially concentric relation with respect to said axis X-X. Said rest 11g with flange 11h is thus positioned to serve as a guard for shielding the tongue, gums and other mouth portions from disc during grinding operation, as is clear from Figs. 5 and 7.

Emma mid-portion of peripheral edge side 11!: of rest 11g there may be provided a suitable length adjustable means, such as, finger actuated upstanding clamping screw 11m which engages in an elongated slot 13m of a horizontally disposed extension arm lip, as is clear from Figs. 5, 6 and 7, the latter being of arcuate cross-sectional shape conforming to the curvature of said edge side 11k, and terminating said arm 11p is a shielding guard llq overhangingly supported for movement toward and away from rest Hg in spaced parallel alignment.

To more positively restrict movement of said arm 11;; with respect to said edge side illk and consequently said alignment of shielding guard Hg with respect to rest 11g, surface portion of said edge side ilk may be grooved to provide an alignment slideway Illr assuring a firm' mounting thereof even when screw 11m becomes accidentally loosened.

cross-sectional contour shape formed with a peripherally-- extending inturned flange 11s radially disposed to project beyond surface 11:, that is, lies in transverse relation with respect to said axis X-X and in concentric relation thereto. An opening llu is provided in shielding guard llq in axial alignment with sleeve 11c of anchoring member 11b through which the free end of mandrel d may extend permitting adjustability of guard-hood 11. Said shielding guard 11g serves to protect the tongue, gums and other mouth portions from being injured by disc 10a during grinding operation.

The utility of the invention will now be apparent.

Assuming that a persons jaw I with three natural teeth missing is to be provided with a replacement of bridgework W between natural teeth T, as shown in Fig. 6, and that said teeth T have abutment surface sides A and B thereof requiring occluso-gingival alignment for said bridgework W, rotary drill cutting means 19 is first assembled with abrasive surface sides 10]: and 10211 of grinding discs 19:: and 19b, respectively, parallelly secured to an adjusted distance spaced apart sufficiently to snugly fit the space between teeth T to be slice cut.

The improved guard-hood 11 is next fitted by frictionally mounting tubular anchoring member 111) to engage drill head H with rest 11g positioned so that the flange 11h serves as a shield guard about disc 10b. Then extension arm 11p is adjustably clamped by means of finger screw 11m so that shielding guard Hg is positioned to extend about disc lira.

Now on inserting complete rotary drill cutting means 10 with said spaced apart discs 19a and 1012 between teeth in occluso-gingival alignment and applying effective grinding power to rotate mandrel 10d, the desired parallel slicing of teeth sides at A and B is either simultaneously produced or during the slight movement of said cutting means in an axial direction to and from said teeth sides A and B and to and from the jaw I.

This slicing movement is continued until surface sides A and B are ground to flat abutment surface areas of desired extent in parallel relation ready for fitting permanent bridgework W. The use of said improved guardhood 11 with support rest 11g, shielding guard llq with flanges 1111 and 11s, respectively, thereof as a safeguarding shield of said abrasive surfaces 10k and 10m extending just short of 180 thereabout assures protection against accidental injury to the tongue, gums and other mouth portions during said slicing operation without interference with the grinding action and without obstructing the full view of the operational areas.

It is thus seen that there is provided an improved guardhood of the character described whereby the several objects of the invention are achieved and which are well adapted ot meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be understood that all matters herein set forth or shown in the accompanying drawing are to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. In a rotary cutting means formed with a hand manipulated drill head and having spaced apart parallelly aligned grinding discs mounted to turn on a mandrel extending through said head, a base element comprising a tubular ended anchoring member for frictionally mounting on said drill head, a sector shaped rest extending from said anchoring member to overhang one of the grinding discs, said rest formed with a peripheral flange to serve as a guard-hood for said grinding disc, and a manual length adjustment fastener means carried by said rest for securing a shielding guard to serve as a second hood for the other of said grinding discs.

2. The rotary cutting means defined in claim 1 in which said tubular ended anchoring member is of circular cross section and has a notch cut on a rim edge thereof 4 for engaging with a projecting stop means provided on said drill head to positively prevent rotation of the anchoring member in said mounted position.

3. The rotary cuttign means defined in claim 1 in which said tubular ended anchoring member is of circular cross section and has a notch cut on a rim edge thereof for engaging with a projecting stop means provided on said drill head to positively prevent rotation of the anchoring member in said mounted position, said adjustment fastener means including a slideway carried by said rest from which the shielding guard is supported in desired spaced apart alignment from said rest.

4. A dental device of the character described for preparing spaced apart natural teeth for permanent bridgework replacing missing teeth having a rotatable mandrel formed with an axially extending arbor portion, comprising spaced apart parallelly aligned grinding discs secured to turn with said arbor portion, said discs having abrasive surfaces facing away from each other for slice cutting said natural teeth to form abutment surface side areas extending in parallel occluso-gingival relation predetermined to correspond to said bridgework, means for adjusting the spaced apart distance between said discs in fixed relation to each other on said arbor portion, a hand manipulated drill head through which said mandrel extends, guard-hoods for said disc abrasive surfaces, a tubular ended anchoring member for said guard-hoods frictionally mounted on said drill head, a sector shaped rest extending from said anchoring member to overhang one of said grinding discs, said rest formed with a peripheral flange to serve as one of said guard-hoods, a manual length adjustment fastener means carried by said rest, and a shielding guard formed with a peripheral flange extending from said fastener means positioned to overhang the other of said grinding discs in adjustable parallel spaced alignment with respect to said first mentioned guard-hood to serve as the other of said guard-hoods.

5. The dental device defined in claim 4 in which said tubular ended anchoring member is of circular cross section and has a notch cut on a rim edge thereof for engaging with a projecting stop means provided on said drill head to positively prevent rotation of the anchoring member in said mounted position, said adjustment fastener means including a slideway carried by said rest from which the shielding guard is supported at a desired spaced aligning distance from said rest.

6. The dental device defined in claim 4 in which said adjustment fastener means includes a slideway carried by said rest and a clamping screw for adjustably securing said anchoring member therein.

7. In a rotary cutting means formed with a hand manipulated drill head and having spaced apart parallelly aligned discs mounted to turn on a mandrel extending through said head, a base element comprising a tubular ended anchoring member for frictionally mounting on said drill head, a sector shaped rest extending from said anchoring member, said rest formed with a peripheral flange for overhanging one of the grinding discs to serve as a guard-hood therefor, a manual length adjustment fastener means carried by said rest, and a sector shaped shielding guard formed with a peripheral flange extending from said fastener means positioned to overhang the other of said grinding discs in adjustable parallel spaced alignment with respect to said first mentioned guard-hood, said shielding guard being formed with a through-opening sized and positioned to receive an end of the mandrel for free rotation therein.

Stanbrough Mar. 19, 1901 Patterson Apr. 21, 1925 

